<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML ><HEAD ><TITLE >Considerations</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Spam Filtering for Mail Exchangers" HREF="index.html"><LINK REL="PREVIOUS" TITLE="Blocking Collateral Spam" HREF="collateral.html"><LINK REL="NEXT" TITLE="Multiple Incoming Mail Exchangers" HREF="multimx.html"></HEAD ><BODY CLASS="chapter" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Spam Filtering for Mail Exchangers: </TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="collateral.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="multimx.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="chapter" ><H1 ><A NAME="considerations" ></A >Chapter 3. Considerations</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT >3.1. <A HREF="multimx.html" >Multiple Incoming Mail Exchangers</A ></DT ><DT >3.2. <A HREF="otherservers.html" >Blocking Access to Other SMTP Servers</A ></DT ><DT >3.3. <A HREF="forwardedmail.html" >Forwarded Mail</A ></DT ><DT >3.4. <A HREF="usersettings.html" >User Settings and Data</A ></DT ></DL ></DIV ><BLOCKQUOTE CLASS="ABSTRACT" ><DIV CLASS="abstract" ><A NAME="AEN1250" ></A ><P ></P ><P > Some specific considerations come into play as a result of system-wide SMTP time filtering. Here we cover some of those. </P ><P ></P ></DIV ></BLOCKQUOTE ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="collateral.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="multimx.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Blocking Collateral Spam</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" > </TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Multiple Incoming Mail Exchangers</TD ></TR ></TABLE ></DIV ></BODY ></HTML >